Genome to Go

It’s already possible to have your own genome sequenced. But personalized medicine based on sequencing still has a way to go

Next month marks the 60th anniversary of the discovery of the double helix structure of DNA by James Watson and Francis Crick. To ordinary folks, the image (known as Photo 51) that confirmed the Watson-Crick model doesn’t look like anything. But without this image—and without the brilliant work of X-ray crystallographer Rosalind Franklin—the Cambridge lads had a theory and a model but no actual proof that DNA was indeed “the molecule of life.” It took Franklin’s technical know-how and perseverance for that secret to be revealed.

Biology is now one of many sciences that’s almost completely dependent on technology: The technologies that allow us to view human biology at the molecular level have driven the genomic revolution. Automation, robotics, high-speed processors, and sophisticated computer programs have taken what was once the painstaking handwork of DNA identification, isolation, preparation, and sequencing and turned them into digital processes. The first sequencing of the human genome took 13 years and US $3 billion. Now machines the size of a multipurpose office printer will soon be able to do the same for sums of about $1000, and all in a day’s time.

But what will this mean on a human level? Eliza Strickland’s article in this issue, “The Gene Machine and Me,” is about her very personal experience with Ion Torrent’s semiconductor-based genome-sequencing machines. These machines, which turn chemical signals into digital form, are the latest demonstration of the powerful electronic technologies driving all things genomic. In an echo of events 60 years ago, when several labs [PDF] competed to discover the true nature of DNA, several companies are now racing to create genomic technology for widespread use.

Why is this significant? After all, for $100 you can already send away a bit of spit to a direct-to-consumer DNA testing company like 23andMe. Their results will tell you if you’re related to Genghis Khan, carry disease traits you could pass on to your children, or have an elevated risk of developing diabetes. These companies use a technology that examines the million points on the genome that vary among individuals.

But being able to predict, prevent, or treat disease based on the sequencing of your entire genome—which is made up of 3 billion components—is a far more complicated business. It’s also more rewarding. The collection and analysis of large sets of individual genomes should eventually help researchers establish the root causes of complex diseases and allow them to create individualized treatment and even cures.

Patient-driven, personalized, “precision medicine” has significant hurdles to overcome, and not just technical ones. One of the most important is how to sequence millions, if not billions, of people to broaden our understanding of which genes correspond to which disease vulnerabilities, as well as other inherited characteristics. And while we’re doing that, we’ll need to develop more big-data software programs to sift through all the information from these genomes—a single human genome alone is about 4 gigabytes.

Other big challenges include training doctors to use genomic information in their practices, getting pharmaceutical companies to give up their blockbuster drug revenue model, and goading insurance companies into abandoning their rigid reliance on actuarial tables. And all this must happen as we simultaneously take on the inevitable genetic discrimination problems and myriad other ethical issues that will spring up.

As the former editor of a biotechnology journal, I have seen lots of breakthroughs, revolutions, and quantum leaps heralded as being on the brink of transforming our lives forever. But these transformations never occur overnight and take years, often decades, to reveal themselves.

That’s the case with human genomics and its impact on medicine. Genetics has been poised to change medicine since Gregor Mendel tended his peas. In 10 years or so, after we’ve all had our genomes sequenced and are toting them around on our tricorders, the benefits for medicine of genome sequencing and its attendant technologies should become truly apparent—as will all the tics and bumps that make each of us uniquely human.

Advertisement
Advertisement